1. Field of the Invention
This invention relates to an image-forming method which makes it possible to provide an image having high density and high resolution and, more particularly, to an image-forming method suitable for providing a recorded image having improved surface gloss. The present invention also relates to an image-forming method suitable for providing a recorded image having improved waterfastness.
2. Description of the Related Art
Conventionally, recording paper such as that described in Japanese Patent Publication No. 26665/1991 and glossy paper such as that described in Japanese Patent Publication No. 36237/1993 have been used as recording mediums for forming images by ink-jet recording methods. The recording paper described in Japanese Patent Publication No. 26665/1991 has a base paper and a coating layer formed on the base paper, the coating layer containing a fine silica powder and a water-soluble binder such as polyvinyl alcohol. The glossy paper described in Japanese Patent Publication No. 36237/1993 has a non-transparent base such as synthetic paper and a film comprising mainly a water-soluble resin and formed on the non-transparent base. Japanese Patent Laid-Open Publication No. 265680/1988 discloses cast-coated paper in which a coating layer comprising mainly silica and a binder is formed by a cast coating method.
Recently, with improvements in the performance of ink-jet recording apparatus, e.g., increase in speed, increase in the number of recording colors and so on, there has been a need for an ink-jet recording medium having various improved properties, e.g.,
(1) high ink absorbing ability and high ink drying speed, PA0 (2) capability of maintaining a high optical density of the dots and freedom from blurring around the dots, PA0 (3) capability of forming a dot shape close to a true circle with a smooth peripheral line, PA0 (4) capability of maintaining improved uniformity of the solid printed portion, or freedom from density unevenness in the solid portion, PA0 (5) capability of forming a sharp boundary even when inks of different colors are printed adjacent each other, PA0 (6) capability of maintaining good waterfastness and light fastness of images such that the images are stably maintained without changing in quality during long-term preservation.
There is also a need for being able to form, by an ink-jet recording method, an image having a high degree of gloss on the surface of a recording medium, and recording on a recording sheet (glossy paper) having surface gloss is also required.
The coated paper described in Japanese Patent Publication No. 26665/1991 has a mat surface tone and has no gloss. On the other hand, a high-gloss and high-density image can be formed on the glossy paper described in Japanese Patent Publication No. 36237/1993. However, since the surface of this paper is formed by a hydrophilic resin coating, the time it takes to dry and fix ink attached to its surface is long, and a printed portion remains sticky long enough to hinder continuous recording. Also, the ink-absorbing speed is so low that non-uniformity of density can occur easily in a solid printed portion. There is also the problem of a formed image being low in waterfastness because the ink-receiving layer is water-soluble.
The cast coated paper for ink-jet recording described in Japanese Patent Laid-Open Publication No. 265680/1988 has good characteristics with respect to drying and fixation of ink, but entails problems in terms of waterfastness of images, blurring at the boundary between different colors (hereinafter referred to as "boundary blur") and uniformity of the solid portion.
Attempts have been made to improve recording sheets to deal with the problems of low solid uniformity and boundary blur, which are serious in an image-forming process using a recording sheet having surface gloss, but satisfactory recording sheets have not been obtained. Also, essentially no attempts have been made to solve these problems with respect to both improving the ink and improving the recording sheets.